Characterize the association between use of oral contraceptives and occurrence of malignant cutaneos melanoma by a case-control study, determine relative risk, causative and confounding factors. Perform the following subsidiary analyses: The relative risk of melanoma associated with different durations of oral contraceptive use; the relative risk of melanoma associated with different formulations of contraceptives; the relative risk of melanoma at various anatomical sites associated with oral contraceptive use; the relative reisk of different clinical stages and histological types of melanoma associated with oral contraceptive use; the relative risk of melanoma associated with estrogen hormone replacement therapy; the relative risk of melanoma among women using oral contraceptives who have intense sunlight exposure, compared with that in women who have little exposure to sunlight.